4l80e swap shift solenoid issue
01-06-2015, 02:24 PM
#11
The relay method works fine when it is needed and properly done.
The 4L80E has very simple electronic controls, especially for shift strategy. On/off. It just does what it's commanded.
I can't even begin to convey how often we have helped customers and other people diagnose their wiring/tuning issues.
It takes the proper tools and some time.
Understanding WHAT you are trying to accomplish and how it works helps.
01-06-2015, 03:01 PM
#12
I'm pretty sure we offered more tech than to just send you to another vendor for a harness.
Diagnosing this type of issue will require the proper tools.
That being a scanner capable of commanding the shift solenoids. Snap on Modus or Solus, HPTuners, EFILive, etc.
A multimeter.
A wiring diagram.
Key on, you MUST have 12V to the E pin AT THE TRANSMISSION.
You must also have power supplied to the relay if you are using that method.
If you command 1st gear, or the A solenoid, you should have continuity to ground from the A wire on the transmission main connector. That means put the multimeter between the A wire and the transmission case or frame and it should show a fairly low ohm reading. 2-3 ohms max. When you turn the solenoid off the ohms should go infinite, NO continuity.
So in 1st and 4th, the A solenoid will he grounded, but not in 2nd or 3rd.
The test is the same for the B wire and solenoid, except it should be on in 3rd and 4th, and off in 1st and 2nd.
If you are using a relay, you will be commanding this "off" to turn it on.
Be sure your relay is a NO/NC relay with a pin 87 and pin 87a. If it's a NC/NC relay it won't work.
Diagnosing this type of issue will require the proper tools.
That being a scanner capable of commanding the shift solenoids. Snap on Modus or Solus, HPTuners, EFILive, etc.
A multimeter.
A wiring diagram.
Key on, you MUST have 12V to the E pin AT THE TRANSMISSION.
You must also have power supplied to the relay if you are using that method.
If you command 1st gear, or the A solenoid, you should have continuity to ground from the A wire on the transmission main connector. That means put the multimeter between the A wire and the transmission case or frame and it should show a fairly low ohm reading. 2-3 ohms max. When you turn the solenoid off the ohms should go infinite, NO continuity.
So in 1st and 4th, the A solenoid will he grounded, but not in 2nd or 3rd.
The test is the same for the B wire and solenoid, except it should be on in 3rd and 4th, and off in 1st and 2nd.
If you are using a relay, you will be commanding this "off" to turn it on.
Be sure your relay is a NO/NC relay with a pin 87 and pin 87a. If it's a NC/NC relay it won't work.
01-06-2015, 04:10 PM
#16
Sorry if it came off rude, I definitely didn't mean it that way. I'm not sure if you are the person who I spoke with on the phone yesterday, but the answer you just typed up was what I was hoping for yesterday. I didn't really want to buy a harness and just have this exact same issue in the end. I want to know what is going wrong. I also sorta figured it was possibly bc I didn't buy a trans from you guys, which is understandable that you didn't wanna spend time to diagnose my issue. Thank you for the reply and I will try this all tomorrow.
I do have to limit my resources and try to concentrate on our paying customers however we try to help anybody we can.
Oftentimes I can give this same explanation and end up trying to teach guys how to use a multimeter over the phone.
Diagnosing these issues requires the proper tools AND some mechanical know how. I can't teach everybody how to use a multimeter over the phone, so when it gets to that point I suggest that someone seek professional help from an experienced technician.
Thread
Thread Starter
Forum
Replies
Last Post
LCHEE
GM Drivetrain & Suspension
10
10-24-2020 04:10 PM
lxcoupe
GM Drivetrain & Suspension
17
07-14-2015 10:14 PM